Routine cytodiagnosis of pulmonary malignancies

Anesthesiologists normally discard the material routinely suctioned from the tracheal tube of patients under general endotracheal anesthesia. We preserved, and later examined microscopically, specimens from 10,621 patients. We found 11 cytologically abnormal smears from subjects with unsuspected pulmonary involvement, an incidence slightly more than 1:1,000. The accuracy of our method was assessed by calculation of the percent of abnormal smears obtained from patients with prediagnosed bronchogenic carcinomas: 40% when suctioned material was immediately spread on slides, and 67% when cellular concentration was achieved by mucolysis followed by filtration or centrifugation. Secretions normally discarded can reveal much information that would otherwise be missed. Our method may be useful if applied to patients at risk (heavy smokers, workers with asbestos, nitrosamine, or benzopyrine, miners of radioactive material, etc) who undergo general anesthesia for incidental surgery.